He said the country has consistently shown that it can elect quality New Zealanders to serve as the Governor-General and "there is no reason why we could not do likewise with a non-executive President in that role".

"We can do so much better than continue to bend our knee to a hereditary monarch on the other side of the world," he said.

Mr Dunne challenged the new Parliament to "seize the moment" and begin the process of wider constitutional reform, starting with making the next Head of State the first President of the Republic of New Zealand.

During his time in Parliament Mr Dunne supported Labour-led Governments for 13 years and National-led Governments for 13 years.

He said he has no time for "histrionic, showman politics, where style outweighs substance, and where an almost childlike narcissistic obsession with being the centre of attention dominates".

Politics was a "sideshow" for many citizens who are too busy getting on with their own lives, he said, and usually the politicians that caught their attention were "the outlandish and the irresponsible".

"Clearly, I failed in that regard but I was and remain proud to have been frequently labelled 'Mr Sensible' or the politician who turned being reasonable into a political art-form."

Mr Dunne announced his resignation from Parliament before the election, and said that becoming a grandparent was his "wake-up call" that it was time for him to stand down.